Proxy Anonmity Levels

Level 1: Elite - connection looks like a regular client (browser) and the server doesn't know that you are using proxy or changed your IP this also known as high anonymouse proxy.
Level 2: Anonymouse - your IP is hidden but target server could still know that you are using a proxy.
Level 3: Transparent - IP is forworded and target server can detect your real IP and knows that you are using proxy also called caching proxy used for caching only.

Common ip proxy ports

we will discuss here briefly the common proxy server ports used
The 1st common port is 3128 which used for http connections and 40% of http proxies use it
The 2nd common port is http 8080 which used for http connections and 30% of http proxies use it
The 3rd common port is 80 which used for http connections and 20% of http proxies use it
The remainig 10% is divided on several ports like 1000, 9090, 8081 ... etc

Most https proxies use port 443 as thier main port.
Most Socks4 and Socks5 proxies use port 1080 as thier primary port.